Submission #1109210

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109210		Gourougourou	Untitled (POI11_wyk)	C++17	0 / 100	30065 ms	3792 KiB

Main

#include <bits/stdc++.h>
 
using namespace std;
typedef long long ll;
typedef pair<double,double> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
#define x first
#define y second
const double EPS = 1e-18;
 
 
double dist(pll a, pll b) {
    return (a.x-b.x)*(a.x-b.x) + (a.y-b.y)+(a.y-b.y);
}
pair<pll,ll> maxDist(vpll v) {
    ll ans = 0;
    pll a = v[0];
    for (pll i : v) {
        for (pll j : v) {
            ll res = dist(i,j);
            if (res > ans) {
                ans = res;
                a = {(i.x+j.x)/2,(i.y+j.y)/2};
            }
        }
    }
    return {a,ans};
}
 
vpll ok(int n, int m, vpll v, double k) {
    vpll ans;
    vpll cur;
    pll prev = {-1,-1};
    for (int i = 0; i<n; ++i) {
        cur.push_back(v[i]);
        auto p = maxDist(cur);
        if (p.y > 4*k) {
            ans.push_back(prev);
            cur = {prev = v[i]};
        }
        else prev = p.x;
    }
    if (!cur.empty()) ans.push_back(prev);
    return ans.size() <= m ? ans : vpll();
}
 
int main() {
    int n, m; cin >> n >> m;
    vpll v(n);
    for (pll &p : v) cin >> p.x >> p.y;
    double lo = 0, hi = 1e18;
    while (hi-lo > EPS) {
        double mid = (hi+lo)/2;
        if (ok(n,m,v,mid).size()) hi = mid;
        else lo = mid;
    }
    vpll ans = ok(n,m,v,hi);
    cout << fixed << setprecision(14);
    cout << sqrt(hi) << '\n';
    cout << ans.size() << '\n';
    for (pll p : ans) cout << p.x << ' ' << p.y << '\n';
}

Compilation message (stderr)

wyk.cpp: In function 'vpll ok(int, int, vpll, double)':
wyk.cpp:45:23: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<double, double> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |     return ans.size() <= m ? ans : vpll();
      |            ~~~~~~~~~~~^~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 7
• Subtask 4: 0 / 7
• Subtask 5: 0 / 8
• Subtask 6: 0 / 8
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• Subtask 10: 0 / 8
• Subtask 11: 0 / 8
• Subtask 12: 0 / 8
• Subtask 13: 0 / 8